Shell mold clamping machine



May 28, 1957 Filed Dec. 4, 1955 W. R. KIDDER SHELL MOLD CLAMPING MACHINE 3 Sheets-Sheet 1 LL 34 52 29 26.35 48 2s I! 55 27 o o o o O o o 0 I] H/ /8 :i I

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ATTORNEY United States Patent SHELL MOLD CLAMPING MACHINE Ward R. Kidder, Kokomo, Ind., assignor to Union Carbide and Carbon Corporation, a corporation of New York Application December 4, 1953, Serial No. 396,219

4 Claims. (CI. 22-90) This invention relates to shell mold clamping machines, and more particularly to clamps of this character for holding together mating shells while molten metal is poured into the mold formedthereby to efiect the casting.

These shell molds are prepared from a mixture of fine sand and an organic thermosetting binder. The wall thickness of the shell is relatively thin, generally'between /s and inch and is therefore somewhat fragile. Heretofore two such shells of sand resin composition have been assembled in mating relation and placed in a box, and supported in contact and against the internal pressure of the molten metal by steel shot poured around the mold.

However, this method of supporting the molds has been expensive, particularly with high priced alloys, because there is generally some spillage of molten metal during pouring of the casting, and it is difficult to reclaim any metal that was spilled. Also, the shot had to be cleaned from the sand resulting from the disintegration of the mold due to heat, and loading and unloading of the supporting box were relatively time consuming operations.

It is therefore the main object of the present invention to eliminate the difliculties referred to above and materially speed up the operation of setting up the mold preparatory to casting. Other objects are to provide a clamp to exert suflicient pressure to maintain the two-halves of the mold in good contact so that no running out or finning of the cast metal occurs, yet not to apply so much pressure as to crush the mold, and to provide a clamp of sufiicient flexibility to accommodate molds of irregular surface contour.

According to the present invention, a group of several individual power actuated tong type clamps are each independently operated on a support in such a manner that when two shells are inserted between the clamping fingers of the tongs, the mold halves are firmly held together without distortion of the mold regardless of surface contour while molten metal is poured into the mold. The power preferably fluid pressure can be immediately relieved after pouring, allowing the casting and mold to be dropped or otherwise delivered from the machine.

The variation in opening between the pair of levers constituting each clamping tong is provided entirely by the pressure in the cylinder controlling that tong. All of the cylinders are actuated by a common source, and the force exerted by the cylinders is regulated preferably by adjusting the air pressure in the manifold for the cylinders.

The support for the group is preferably a shaft on which each pair of arms is freely rotatable to adapt themselves to the contour of the mold being clamped. The entire clamping assembly may be indexed on the shaft into convenient position for pouring.

The ratio of the arm length from the shaft toward the cylinder with respect to the arm length from the shaft toward the mold, is a constant, preferably 1:2, so that uniform pressure is applied over the whole surface of the mold. Preferably the respective tongs are of different lengths and interchangeably mounted on the shaft to permit the clamping fingers to be distributed over the surface of the mold.

The clamping fingers are rotatably adjustable on the ends of the lever arms mainly in order to bring the mold partly outside of the clamping mechanism into an easily accessible position for pouring of the casting. These fingers are prepared from ordinary hot-rolled steel bar and are easily replaced in the event of damage by spilled metal.

The supporting shaft for the group of tongs is preferably journaled on a post for indexing into selected angular positions. The post is adjustable in height and mounted on a pedestal pivoted on a base and angularly adjustable about its pivot.

In the drawings:

Figure l is a perspective side view of the shell mold clamping machine according to the preferred embodiment of the present invention;

Figure 2 is a perspective end View of the same;

Figure 3 is an end elevation of Figure 4; and

Figure 4 is a side elevation of a portion of the machine shown in Figures 1 and 2.

The shell mold clamping machine shown in the drawings comprises a base 10- on which is pivoted a pedestal 12 adapted to swing about a pintle 14. The pedestal is held at an adjusted angle by a set screw 15 in a telescopic strut 16'. The pedestal 12 slidably receives a supporting post 18 held at adjusted height by a pin 20.

As shown in Figure 4, the top of the post 18 forms a bearing 22 in which is journaled a clamp supporting shaft 25. An indexing plate 26 is secured to the bearing 22 and a hub 27 is secured to the shaft 25. A handle 28 is pivoted on the hub 27, and has a spring pressed pawl 29 to engage notches in the rim of the indexing plate 26.

A plurality of pairs of oppositely disposed levers 30 and 32 are pivoted on the shaft 25 which constitutes a support therefor, and the levers are operated by air cylinders 34. Between the inner end of the bearing 22 and the nearest pair of levers, the shaft 25 has rigidly secured thereto a bracket 35, which supports at the upper end thereof an air manifold 36.

Thebottom of the bracket 35 has secured thereto a pair of retaining bars and 4-2, the opposite ends of which are secured to a transverse frame end bar 43 in turn rigidly secured to the corresponding end of the shaft 25. The retaining bars 40 and 42 have individual adjusting screws 44for each lever, to limit the opening movement thereof.

Asshown in Figure 3,. each clamping lever 30 and 32 has an inwardly extending pad for a bearing 45 journaled on the shaft 25. The top of each lever 30 is pivoted-at 46 between parallel bars 48 secured to the housing of air cylinder 34. The piston rod 50 is secured to one end of a yoke 52, the other end of which is a fork 54 which receives the top of the other clamping lever 32 and is pivoted thereto by a pin 56. A similar yoke 58 connects the lever 30 to the air cylinder mounted on the clamping lever 32.

The pairs of levers 30 and 32 are graduated in different lengths, and the lower ends of these levers carry shell engaging fingers 62 which are rotatably adjustably mounted therein to engage the mold M and permit access to its pouring gate G.

Fluid under pressure, such as compressed air is supplied by a line 70 through a pressure regulator 64 and a line 65 to a valve 66 having a treadle 67. From the valve 66 the pressurized fluid is transmitted through a line 68 to the manifold 36, which distributes the same pressure through lines 69 to the cylinders 34.

In operation, the different lengths of pairs of levers 30 and 32 are selected and arranged to best suit the particular irregularities of the mold to be poured, and theclampin'g 3 fingers 62 are adjusted to bring the mold M partly out of the clamping mechanism so that the pouring gate G is clear of the frame end bar 43 and in easily accessible position.

The treadle 67 is then depressed to supply equal pressure to the cylinders 34 to urge the levers 30 and 32 apart causing the fingers 62 to engage the mold under the same pressure regardless of the depth in the irregular contour engaged by a particular finger.

To further facilitate access to the pouring gate G, the head H may be indexed by the handle 28, the height adjusted by the pin 20, and the angle of the pedestal adjusted by the set screw 15.

What is claimed is:

1. Shell mold clamping machine for holding together mating shells of irregular contour, comprising a support, a group of pairs of oppositely disposed levers pivoted intermediate their ends on said support, each pair of said levers having a corresponding pair of opposed shell engaging fingers secured at their ends toward the mold for engaging said irregular contour at different depths, said support comprising a common shaft, said levers being pivoted thereon in side-by-side relation to distribute said fingers over the length of the shell, the lengths of said pairs of levers being varied to distribute said fingers over the width of the shell, a power actuated device for urging the opposite ends of each pair of said levers apart to urge the shell engaging fingers toward each other, the length of the power actuated arm of each lever being in the same ratio to the mold engaging arm of the same lever throughout the group, and means for distributing the same power to each of said power actuated devices to engage said fingers with said shells with the same pressure at their respective depths.

2. Shell mold clamping machine for holding together mating shells of irregular contour, comprising a support, a group of pairs of oppositely disposed levers pivoted on said support, a mold engaging finger secured to the end of each lever of each pair toward the mold, said support comprising a common shaft, said levers being pivoted thereon in side-by-side relation to distribute said fingers over the length of the shell, the lengths of said pairs of levers being varied to distribute said fingers over the width of the shell, a fluid pressure device for urging the opposite ends of said levers apart to urge the mold engaging fingers of each pair toward each other, the length of the power actuated arm of each lever being in the same ratio to the mold engaging arm of the same lever throughout the group, and said levers being interchangeably mounted on said shaft to adapt the mold engaging fingers to shells of different contour, and a manifold for supplying fluid under the same pressure to each of the fluid pressure devices of said group, whereby said fingers engage said shells with the same pressure at their respective depths.

pairs of levers being varied to distribute said fingers over the width of the shell, the mold engaging fingers being rotataby mounted on the levers and extending at an angle thereto to adapt the mold engaging fingers to irregularities of contour, a cylinder secured to the opposite end of one lever of each pair, a piston in said cylinder secured to the corresponding opposite end of the other lever of each pair for urging said opposite ends apart to urge said mold engaging fingers toward each other, the length of the power actuated arm of each lever being in the same ratio to the mold engaging arm of the same lever throughout the group, and a manifold for supplying fluid under the same pressure to each of the cylinders of said group, whereby said fingers engage the said shells with the same pressure at their respective depths.

4. Shell mold clamping machine for holding together mating shells of irregular contour comprising a base, a pedestal pivoted on a horizontal axis on said base, means for securing said pedestal in selected angular positions in a vertical plane about its horizontal pivot with respect to said base, a support mounted on said pedestal, a group of pairs of oppositely disposed levers pivoted on said support, mold engaging fingers on said levers, said support comprising a common shaft, said levers being pivoted thereon in side-by-side relation to distribute said fingers over the length of the shell, the lengths of said pairs of levers being varied to distribute said fingers over the width of the shell, and means for moving said levers about their pivots to engage said mold engaging fingers with the sides of a pair of mating shells therebetween the length of the power actuated arm of each lever being in the same ratio to the mold engaging arm of the same lever throughout the group.

References Cited in the file of this patent UNITED STATES PATENTS 1,453,176 Perrine Apr. 24, 1923 2,015,975 Sulprizio Oct. 1, 1935 2,088,123 Toman July 27, 1937 2,186,019 Hagemeyer Jan. 9, 1940 2,399,824 Pressman May 7, 1946 2,569,863 Morin Oct. 2, 1951 2,651,822 Davis Sept. 15, 1953 2,736,936 Grueneberg et al. Mar. 6, 1956 

